cmake embed_txtfiles

`embed_txtfiles` 是一个自定义 CMake 函数，用于将多个文本文件嵌入到可执行文件中，以便在运行时读取这些文件内容。下面是一个示例函数的实现：

function(embed_txtfiles target_name)
    set(output_file "${CMAKE_CURRENT_BINARY_DIR}/${target_name}_embedded_files.c")
    set(files_var_name "${target_name}_EMBEDDED_FILES")
    set(var_name "${target_name}_EMBEDDED_FILES_DATA")

    # Collect the file contents and embed them as char arrays
    set(srcs "")
    set(${var_name} "")
    foreach(file ${ARGN})
        file(READ ${file} contents)
        string(REPLACE "\"" "\\\"" contents "${contents}")
        string(REPLACE "\n" "\\n\"\n\"" contents "${contents}")
        list(APPEND srcs "${CMAKE_CURRENT_BINARY_DIR}/temp/${file}.c")
        set(${var_name} "${${var_name}}static const char ${file}_data[] = \"${contents}\";\n")
        set(${var_name} "${${var_name}}static const size_t ${file}_size = ${CMAKE_CURRENT_BINARY_DIR}/temp/${file}_size;\n")
    endforeach()

    # Generate the C code that will be compiled into the executable
    file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/temp")
    file(WRITE ${output_file} "${${var_name}}\n")
    foreach(file ${ARGN})
        file(SIZE ${file} size)
        set(size_var "${CMAKE_CURRENT_BINARY_DIR}/temp/${file}_size")
        file(WRITE ${size_var} "${size}")
        file(APPEND ${output_file} "extern const char ${file}_data[];\n")
        file(APPEND ${output_file} "extern const size_t ${file}_size;\n")
    endforeach()
    file(APPEND ${output_file} "\nvoid ${target_name}_init() {\n")
    foreach(file ${ARGN})
        file(APPEND ${output_file} "  resource_manager_add_resource(\"${file}\", ${file}_data, ${file}_size);\n")
    endforeach()
    file(APPEND ${output_file} "}\n")

    # Compile the generated C code into a library that can be linked into the target
    add_library(${files_var_name} STATIC ${srcs})
    target_compile_definitions(${files_var_name} PRIVATE ${var_name}=${var_name})
    target_include_directories(${files_var_name} PUBLIC "${CMAKE_CURRENT_BINARY_DIR}/temp")

    # Add a custom command to generate the C code and compile it before building the target
    add_custom_command(
        OUTPUT ${srcs}
        COMMAND ${CMAKE_COMMAND} -E copy ${ARGN} "${CMAKE_CURRENT_BINARY_DIR}/temp"
        COMMAND ${CMAKE_COMMAND} -E touch ${output_file}
        DEPENDS ${ARGN}
        COMMENT "Embedding TXT files in ${target_name}"
    )

    # Add the custom command as a dependency of the target
    add_dependencies(${target_name} ${files_var_name})

    # Link the embedded files library into the target
    target_link_libraries(${target_name} ${files_var_name})
endfunction()

使用此函数的示例：

add_executable(myapp main.c)
embed_txtfiles(myapp data/file1.txt data/file2.txt)

在这个示例中，`embed_txtfiles` 函数将 `data/file1.txt` 和 `data/file2.txt` 嵌入到 `myapp` 可执行文件中。在运行时，可以使用 `resource_manager_get_resource("data/file1.txt")` 和 `resource_manager_get_resource("data/file2.txt")` 来获取这两个文件的内容。